Preparation of photographic packet emulsions by a water-in-oil system



Sept. 16, 1958 W. O. KENYON ETAL PREPARATION OF PHOTOGRAPHIC PACKET EMULSIONS BY A WATER-IN-OIL SYSTEM Filed Sept. 1, 1955.

WA TE R- SOLUBLE ,S4L7' OF RES/N COUPLER GELA 77NO S/L VER HAL/DE EMUL S/O/V S 7' IRRE D HARDENED PACKETS OF GELAI/M SILVER HAL/OE AND RES/N COUPLER IN MINERAL O/L -W/LL/AM O. KENYON LOU/S M. M/NSK INVENTORS M! I QMM ATTORNEYS United States Patent PREPARATION OF PHOTGGRABHIC PACKET EMULSIQNS BY A -WATER-elN-0ILSYSTEM William '0. Kenyon and Louis 'M. Minsk, Rochester,

N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application September 1, 19.55,'Serial No. 532,080

5Claims. (Cl.9697) @emulsion .with a resin coupler of the composition defined rhelow or other non-diffusing, water-solublegcoupler, and adispersing this emulsionecontaining coupler in an oily or hydrophobic liquid, hardening the emulsion particles while in finely dispersed formin the oily liquid and then removing the hardened packets and redispers'ingthem, together with other similarly formed packets, if-desired, in=plain,gelatin or other hydrophilic colloid.

The-accompanying drawing is'a flow sheet illustrating .the steps in our process.

The resin couplers which we propose to use have the 'following recurring structure:

where R is hydrogen or a phenyl, alkyl, alkoxy, .carboxyalkyl or acyloxy radical, or and y .are .0 .or 1, :R' represents a color-forming group capable of reacting with the oxidation product of a primary aromatic amino developing agent on photographic development, and R" is hydrogen oran alkyl radicaLe. g., methyl or ethyl, said color-forming material containing an arylgroup.

According to our invention, a solution of the 1sodi- V um salt or other water-soluble saltof the resinrcoupler .is added to the silver halide emulsion and ;a solution .of the resin coupler in the silver halideemulsion formed as shown in the three boxes at the .top'of -.the.drawing. This emulsion is then added to a viscous hydrocarbonoil, for example, mineral oil containing diglycerol .mono laurate as a dispersing agent, .a gelatin hardener .added to the mixture and the mixture stirred until finely vdispersed hardened particles of gelatin, silver halide vand resin coupler in the mineral oil .or other oily liquid .are obtained. The hardened particles or packets are .then

ifiltered or otherwise removed from the dispersion and 1m .y,.however, .the employed such as gprojection through orifices, spinning or vibrating in the oil phase, ultrasonic vibration, various .forms of colloid mills, etc.

Example 1 One gram of a resin coupler of Example 120f U. S. Patent 2,698,797 was dissolved in a solution of 7 'ec. of 0.5 N sodium hydroxide and 10 -cc. of distilled water. -This solution was added to grams of a red-sensitive silver bromoiodide emulsion at 40 C. The-pH of the emulsion was then adjusted-to-6.06'at40-Cvwithaqueous citric acid. The total weightwas then '124 grams.

To 200 cc. of mineral oil (Nujol) in a one-liter'beaiker immersed in a water bath at 45 C. and stirred -in a mixer with a 2" propeller 'was added dicresyl monolaurate in an amount of 2% based-on the weight o'f- 'oil. To this was added 25 cc. of .the above emulsion at 40 C. and the mixture was stirred for ten minutes. Two '-cc.-o'f a 5% aqueous solution-of mueochloric ac i'd was added at 40 C. and stirring was continued *overnight while the bath temperature was'perm'itted "to drop spontaneously to room temperature (the bath dropped toroom temperature in about .2 hours). After about 15 hours .the mixture was chilled by placing ice-and water ,in the bath .and maintained at 10 or lower .for .15 minutes. Throughout .the following operations all liquids were cooled to 10 or less before addition and the beaker and contents were .kept .in an ice 'bath. Five hundred vcc. of petroleum ether were .then added slowly with .continued stirring. Immediately afterthe addition ofthe petroleum ether the propeller waschanged to .a 1 /2 size, and .the mixture was stirred for 2 minutes. 'The stirrer .was then removed and the packets allowed to settle. When the packets had settled to the bottom the supernatent liquid was poured 01f 'and 500 cc. of 'fresh petroleum ether-was added withstirring and thestirr'ing, set- .tling .and decanting process repeated. Onehundred cc. of petroleum ether was then added .and .after stirring, 5.00 .cc. .of absolute alcohol was poured in over ,a 'period of about 30 seconds. The suspension was stirred for 5 minutes-and the packets were filtered onto ,aBuchner funnel. They were washed on the funnel with fresh portions of alcohol. The packets were dried .at room temperature with occasional stirring .to prevent matting. The average particle size was about 3 to '5 microns.

Example 2 To 100 grams of a blue-sensitive gelatino silver brornoiodide emulsion of the same kind as used in Example l there'was added with stirring at 40 C. a-solution of the'following resin coupler made 'by dissolving -1 gram of the coupler in a solution 0157 "cc. 'of'0i5 N 'sodium'hy- 'droxide and '10 cc. of water.

This coupler is similar to that of? Example 8 .of U. vS.

Patent 2,698,797, but was made from vinyl acetatemaleic anhydride instead of styrene-maleic anhydride resin. The pH of the resulting emulsion was adjusted with citric acid to 6.1. The viscosity of this emulsion dropped during the reduction in pH and appeared to reach a minimum at 6.5. Solution could therefore be carried out at this pH.

Packets were then prepared by dispersing this emulsion in the same way as described in Example 1. Packets were obtained having an average size of 3 to 10 microns Example 3 A mixture of 1.5 grams of the resin coupler of Example 14 of U. S. Patent 2,698,797 and 10 cc. of 0.5 N sodium hydroxide were heated on a steam bath. When a moderately high viscosity was reached the dope was diluted with 10 cc. of water and the heating and stirring was continued until solution was complete. The pH of this solution after cooling to room temperature was then adjusted to 8.75. The total weight was 25 grams. 12.5 grams of this solution was added at 40 C. to 50 cc. of a greensensitive gelatino-silver bromoiodide emulsion of the same composition as that used in Example 1 and well stirred. There appeared to be little viscosity change. The pH was adjusted to 6.72 with 10% aqueous citric acid.

Packets were then prepared by adding the emulsion to mineral oil as described in Example 1 except that 1 cc. of chromic chloride solution (2 grains per cc.) was added in place of the mucochloric acid as a hardener. Packets were obtained having a particle size of 3 to microns.

Example 4 The packet emulsions prepared as described in Examples 1 to 3 were mixed with gelatin and coated on film base to form a three-color, single-layer mixed packet dispersion.

Example 5 To 200 cc. of mineral oil at 45 containing d-iglycerol monolaurate was added 4 cc. of a solution of 2-vinylpyridine polymer metho-p-toluenesulfonate solution. The pH of the vinylpyridine polymer quaternary salt had previously been adjusted to 7.07 with 40% aqueous sodium hydroxide solution. The suspension was stirred for 3 minutes and then 20 cc. of the coupler dispersion described below was added at 40. The packets were then hardened with mucochloric acid and then separated from the dispersion as described in Example 1. The packets thus obtained were slightly sticky and averaged about 5 microns in diameter.

The coupler dispersion was made by diluting 298 g. of a slow gelatino-silver bromoiodide emulsion with 175 cc. of water and adding 48 cc. of coupler solution, and then adjusting the pH of the mixture to 6.5 with citric acid While stirring.

The coupler solution was made by mixing 8.3 g. of the magenta coupler l-phenyl-3-i3'{2-(2,4-di-tert. amylphenoxy) 4 o sulfobenzamido} benzamido benzamidol- S-pyrazolone, 20 cc. of ethyl alcohol, and 4.4 cc. of 20% sodium hydroxide solution, stirring the mixture at 104 F., and after 3-4 minutes'adding 47 cc. of water, and stirring for a few minutes to give a clear solution of the coupler.

In using couplers of the type described in Example 5, mordants other than the polyvinyl pyridine quaternary salt may be used such as piperidyl cellulose, polyvinyl piperidine, chitosan, the polymeric biguanides, or N-alkylamino celluloses, e. g. N-n-butly amino cellulose.

Packets made according to our invention may be used for black-and-white development by omitting the coupler from the packet.

The preparation of the resin couplers used according to our invention is described in Godowsky and Minsk 4 lyl styrene-maleic acid interpolymers described in Laakso and Allen U. S. Patent 2,646,421.

It will be understood that the examples included herein are illusrative only and that our invention is to be taken as limited only by the scope of the appended claims.

We claim:

1. The method of making a packet photographic emulsion which comprises mixing with a gelatino-silver halide emulsion a water-soluble salt of a water-soluble coupler capable of reacting with the oxidation product of a primary aromatic amino developing agent on photographic development to form a dye and non-diffusing in photographic gelatin layers, to form a solution of said coupler in said emulsion, mixing said emulsion with a viscous hydrocarbon oil and forming a dispersion of said emulsion in said oil, adding a gelatin hardening agent to said dispersion to harden the dispersed emulsion particles, removing the dispersed particles from said oil and redispersing them in gelatin to form a dispersion of particles of gelatin, silver halide and coupler in a matrix or continuous phase of gelatin. Y

2. The method of making a packet photographic emulsion which comprises mixing with a gelatino-silver halide emulsion a water-soluble salt of, a resin-coupler nondifiusing in photographic gelatin layers and having the recurring structure where R is selected from the class consisting of hydrogen, phenyl, alkyl, alkoxy, carboxyalkyl and acyloxy radicals, x and y are selected from the class consisting of 0 and l, R represents a color-forming group including an aryl group, capable of reacting with the oxidation product of a primary aromatic amino developing agent on photographic development to form a dye, and R" is selected from the class consisting of hydrogen and an alkyl radical, to form a solution of said resin-coupler in said emulsion, mixing said emulsion with a viscous hydrocarbon oil and forming a dispersion of said emulsion in said oil, adding a gelatin hardening agent to said dispersion to harden the dispersed emulsion particles, removing the hardened emulsion particles from the dispersion, and redispersing said particles in gelatin to form a dispersion of particles of hardened gelatin, silver halide and resin-coupler in a matrix or continuous phase of gelatin.

3. The method of making a packet photographic emulsion which comprises mixing with a gelatino-silver halide emulsion a water-soluble salt of a resin-coupler of the recurring structure where R represents a color-forming group including an aryl group, capable of reacting with the oxidation product of a primary aromatic amino developing agent on photographic development to form a dye, thereby forming a solution of said resin-coupler in said emulsion, mixing said emulsion with a hydrophobic liquid and forming a dispersion of said emulsion in said liquid, adding a gelatin hardening agent to said dispersion to harden the dispersed emulsion particles, removing the hardening emulsion particles from the dispersion, and redispersing said particles in gelatin to form a dispersion of particles of hardened gelatin, silver halide and resin-coupler in a matrix or continuous phase of gelatin.

4. The method of making a packet photographic emulsion which comprises mixing with a gelatino-silver halide emulsion a water-soluble salt of a resin-coupler of the recurring structure aryl group, capable of reacting with the oxidation product of a primary aromatic amino developing agent on photographic development to form a dye, thereby forming a solution of said resin-coupler in said emulsion, mixing said emulsion With mineral oil and forming a dispersion of said emulsion in said mineral oil, adding a gelatin hardening agent to said dispersion to harden the dispersed emulsion particles, removing the hardened emulsion particles from the dispersion, and redispersing said particles in gelatin to form a dispersion of particles of hardened gelatin, silver halide and resin-coupler in a matrix or continuous phase of gelatin.

5. The method of making a packet photographic emulsion which comprises mixing with a gelatino-silver halide emulsion a water-soluble salt of a resin-coupler of the recurring structure (JO-CH:

to form a solution of said resin-coupler in said emulsion, mixing said emulsion with mineral oil and forming a dispersion of said emulsion in said mineral oil, adding a gelatin hardening agent to said dispersion to harden the dispersed emulsion particles, removing the hardened emulsion particles from the dispersion, and redispersing said particles in gelatin to form a dispersion of particles of hardened gelatin, silver halide and resin-coupler in a matrix or continuous phase of gelatin.

References Cited in the file of this patent UNITED STATES PATENTS 2,284,877 Martinez June 2, 1942 2,618,553 Baines et a1 Nov. 18, 1952 2,698,794 Godowsky Jan. 4, 1955 

1. THE METHOD OF MAKING A PACKET PHOTOGRAPHIC EMULSION WHICH COMPRISES MIXING WITH A GELATINO-SILVER HALIDE EMULSION A WATER-SOLUBLE SALT OF A WATER-SOLUBLE COUPLER CAPABLE OF REACTING WITH THE OXIDATION PRODUCT OF A PRIMARY AROMATIC AMINO DEVELOPING AGENT ON PHOTOGRAPHIC DEVELOPMENT TO FORM A DYE AND NON-DIFFUSING IN PHOTOGRAPHIC GELATIN LAYERS, TO FORM A SOLUTION OF SAID COUPLER IN SAID EMULSION, MIXING SAID EMULSION WITH A VISCOUS HYDROCARBON OIL AND FORMING A DISPERSION OF SAID EMULSION IN SAID OIL, ADDING A GELATIN HARDENING AGENT TO SAID DISPERSION TO HARDEN THE DISPERSED EMULSION PARTICLES, REMOVING THE DISPERSED PARTICLES FROM SAID OIL AND REDISPERSING THEM IN GELATIN TO FORM A DISPERSION OF PARTICLES 